Since cameras have the functions of taking pictures and transmitting instant images, many users have applied the cameras as remote monitoring devices to production line managements as well as other areas, such as road condition monitoring and public security monitoring. In general, the cameras available in the present day include a variality of conventional analog cameras and recent popular web cameras. The conventional analog cameras have the features of high photographic quality and stable signal transmission, and thus the analog cameras were put in a very important position in the past. In general, the installation of the analog camera usually requires users to connect an end of a coaxial cable to the analog camera and another end of the coaxial cable to an input terminal of a screen or a recording device installed with a hard disk, and then connect the recording device to the screen, such that the recording device can record an image of a picture taken by the analog camera, and the screen can play the image transmitted from the analog camera at the same time. Therefore, related people can view the image played on the screen for the monitoring task.
However, as the network technology advances, the photographic level and the signal transmission quality of a web camera are improved continuously to catch up with the level of the analog camera and meets market requirements, and many users start using web camera as a main remote monitoring device to replace the analog camera. It is noteworthy to point out that the so-called web camera is not necessarily a web camera installed in a computer system, but it generally refers to an IP camera with a network connection function. In addition the optical components required for taking pictures, the web camera also includes a microprocessor, a memory and a network connection module (such as a network card or a network chip). Compared with the conventional analog camera, the web camera obtains electric power through a network cable, and thus users no longer need additional electric wires and related electric equipments for the installation of the web camera and can save the hardware cost effectively.
As to the installation of the web camera, users have to build a virtual local area network (VLAN) by a gateway device (such as a switch, a router and a modem), connect the web camera and the gateway device by a network cable, and add the web camera to the virtual local area network by a manual setting, so that the gateway device can communicate with the web camera. After the web camera takes a picture to obtain a video signal and converts the video signal into a video packet, the video packet can be transmitted to the gateway device through the virtual local area network. However, the virtual local area network built by the gateway device generally contains other devices, such as a personal computer, and an Internet TV, etc. Since the packets sent by various different devices and the video packets produced by the web camera will be mixed in the virtual local area network and cannot be identified or divided into different transmission rates, and the gateway device is unable to automatically improve the transmission rate of the video packets, the problems of packet loss, transmission delay and low video quality inevitably occur while transmitting the video packets through the gateway device.
Although users can connect a web camera to a gateway device and add a port of the gateway device connected with the web camera to a virtural local area network (VLAN) designated by the gateway device when the gateway device is configuring ports of the VLAN, and adjust priority setting of the ports of the VLAN, such that the video packet produced by the web camera and received by the gateway device through the port can be transmitted with the first priority. However, the aforementioned setting procedure involves professional network knowledge which is too complicated for ordinary users. If a user wants to change the installation position of the web camera, the user has to reconfigure the aforementioned setting. Obviously, such application not only wastes a user's precious time, but also lowers the installation efficiency significantly.
It is an important subject for the present invention to overcome the shortcomings of the installation of a conventional web camera, improve the video packet transmission quality, and solve the packet loss and transmission delay problems.